1. Field of the Invention
The present invention generally relates to handwritten character input devices, and more particularly, to a handwritten character input device provided with a system program for operating in response to pen input usable with an application program adapted to mouse input and keyboard input and not adapted to pen input. More specifically, the present invention relates to a handwritten character input device such as a pen input type computer including a handwritten character recognition function not in the application program but in the system program.
2. Description of the Background Art
In preparing a sentence using a general computer, software for preparing a sentence is read, and the computer is operated according to the software. This software corresponds to an application program, and keyboards and mouses are used as its general input devices.
On the other hand, a computer has been recently proposed which carries out input operation with a pen type input device (hereinafter referred to as a "pen"). In this computer, characters are input and edited by designating a position by means of a pen, or by recognizing characters and editing symbols (such as a calibration symbol and a gesture) written with a pen, instead of a keyboard or a mouse. Such a pen input type computer is described in the article entitled "Birth of Handwritten Input OS", Nikkei Electronics of Apr. 15, 1991 (No. 525), pp. 115-133, published by Nikkei B P, Ltd., and known generally.
Actual operation of a pen input type computer is divided into the following two cases. The first case is to operate the pen input type computer by launching only a specific program using a function, library, or the like for pen input only. More specifically, the first case uses a program for pen input only. In this case, an area in which a character or an editing symbol can be written is designated by using a library, function, or the like for pen input only. When the area allowing writing is designated, the user can write a character or a symbol in this area. Then, the written character or symbol is recognized, and each processing such as input and editing is carried out based on the result of recognition.
Description will be given of a specific example of the above case with reference to FIGS. 1A and 1B. FIG. 1A shows a state at the time of writing, and FIG. 1B shows a state where the result of recognition is displayed after writing.
Referring to FIGS. 1A and 1B, DSP indicates a display screen, LWN indicates a window generated by an application program, LMSG indicates a message displayed by the application program, LAR indicates a writing area, LHS indicates a handwriting, and LRC indicates the result of recognition of the handwriting.
Referring to FIG. 1A, the application program declares the size of the writing area LAR (length, width, and position (upper left position on the area)) by a library for pen input only. The system program detects coordinate data of the handwriting LHS written in the writing area LAR, and displays the handwriting LHS in the writing area LAR.
By detecting no other operation for a prescribed time, completion of writing is determined. As shown in FIG. 1B, the handwriting LHS is recognized, and a character code of the recognition result LRC is supplied to the application program as a result of the library (function) for pen input only. Based on the recognition result, the application program displays the recognition result, that is, characters "ABC" in the figure.
In FIGS. 1A and 1B, one writing area LAR is set. However, a plurality of writing areas can be set. When a pen is operated outside the writing area LAR, the system program supplies the coordinate to the application program in the same form as that of mouse input.
The second case of the actual operation will now be described. In the second case, a pen is operated as an input device without changing the existing application program using a keyboard or a mouse as an input device. More specifically, in order to use pen input with the existing application program not adapted for pen input, a system program processing the pen input is used.
In this case, a system program for pen input called FEP (Front End Processor) or pen input OS (Operating System) displays a special writing frame for writing a character or an editing symbol. When a character or an editing symbol is written in this writing frame, the character or editing symbol is recognized, and the recognition result is supplied to a window (application program) having a keyboard focus in the same form as that of keyboard input. As a result, the application program receives the recognition result of the character or editing symbol, and carries out various processings such as input and editing based on the recognition result.
A window having a "keyboard focus" refers to a window to which key input is applied through a keyboard when a plurality of application program windows are opened in a multi-window system. The window having a keyboard focus is generally set by clicking a mouse after positioning a mouse cursor in a desired window.
A specific example of the above described second case is shown in FIGS. 2A to 2C. FIG. 2A shows a state before writing, FIG. 2B shows a state where a recognition result is displayed after writing, and FIG. 2C shows a state where an application program receives and displays the recognition result.
Referring to FIGS. 2A to 2C, FWN1 and FWN2 show windows generated by a first application program and a second application program, respectively. FMSG1 indicates the content of a message displayed by the first application program, and FCU indicates a cursor for character input. FWNP indicates a window of FEP. FWK1 to FWK3 each indicate a writing frame for writing a character, which also serves as an area displaying a recognition result. FHS1 to FHS3 each indicate handwriting display. FRC1 to FRC3 each indicate the recognition result. FCH1 to FCH3 each indicate a character input based on the recognition result. FRBT indicates a button for supplying the recognition result to the application program.
As shown in FIG. 2A, when characters are written in the writing frames FWK1 to FWK3, FEP displays the respective handwritings FHS1 to FHS3. FEP determines change of the writing frames in which characters are written and no other operation for a prescribed time as completion of writing, and displays the recognition results FRC1 to FRC3 as shown in FIG. 2B. When the button FRBT is touched with a pen, FEP supplies a character train of the recognition results FRC1 to FRC3 to a window having a keyboard focus in the same form as that of keyboard input.
When the window FWN1 has a keyboard focus, FEP supplies the character train of the recognition results FRC1 to FRC3 to the window FWN1, and the first application program receives the recognition results FRC1 to FRC3. As a result, as shown in FIG. 2C, the first application program displays the same character train of FCH1 to FCH3 as that of the recognition results FRC1 to FRC3 at the cursor position FCU. After supplying the recognition results FRC1 to FRC3 to the application program, FEP erases the characters in the writing frames FWK1 to FWK3, and prepares for the next writing.
Supplying pen input converted into keyboard input or mouse input to an application program is described in Japanese Patent Laying-Open Nos. 5-197478, 5-127824, and the like, and well known. An actual pen input OS such as "Windows for Pen Computing" of Microsoft Corporation in the United States carries out processing for outputting a handwriting coordinate of a pen to an application program in the same form as that of mouse input in order to operate with a pen the existing application program using a keyboard or a mouse as an input device. As a result, operation equivalent to that of a keyboard or a mouse is carried out with a pen. The processing using a pen for carrying out operation equivalent to the case of keyboard input is called keyboard emulation. The processing using a pen for carrying out operation equivalent to the case of mouse input is called mouse emulation.
As described above, in the example of the second case, the processing of pen input is left to the system program. Therefore, a conventional existing application program can be used without changing. However, as shown in FIGS. 2A to 2C, writing characters in the writing frame FWNP positioned distant from a desired input position (the cursor FCU position) gives the user uncomfortableness, and the operation is troublesome. Therefore, the above described "Windows for Pen Computing" provides a library only for implementing a circumstance in which writing can be directly carried out in a window. Development of a new application program using the library would allow pen input directly to a window.
As described above, in the existing application program for keyboard input and mouse input and not for pen input, it was not possible to carry out direct pen input in a window displayed by the application program. Further, in order to implement this, it was necessary to write a new application program adapted to pen input.
In addition, as described above, many of the existing application programs use a keyboard or a mouse as an input device. In operating such an existing application program with a pen, it is desired to directly write a character or the like at an arbitrary position in a window displayed by the application program or in a screen.